Circuit-breaking apparatus



April 11, 1933. L. ROEBEL CIRCUIT BREAKING APPARATUS Filed March 9, i928 2 Sheets-Sheet l //v VEN TOE wow/5 E0555;

HTTOENEK April 11, 1933. ROEBEL CIRCUIT BREAKING APPARATUS Filed March 9, 1928 2 Sheets-Sheet 2 /N VEN7UE= Luow/c; P015551 QTRJENEX Patented Apr. 11, 1933 UNITED STATES PATENT OFFICE LUDWIG- ROEBEL, OF MANNHEIM', GERMANY, ASSIGNOR T0 AKTIENGESELLSCHAFT BROWN, BOVERI & OIE., OF IBADEN, SWITZERLAND, A JOINT-STOCK COMPANY OF SWITZERLAND CIRCUIT-BREAKING APPARATUS Application filed March 9, 1928, Serial No.

This invention relates to improvements in circuit-breaking apparatus.

The opening of so-called high-speed circuit breakers constructed heretofore occurs through the action of a spring which acts either directly on the movable breaker contact or acts to release the breaker through a suitable latching device. The opening time proper of these high-speed breakers is very short, but the total time elapsing from the beginning of the short-circuit until the end of the interruption is still relatively long due to the relatively large moment of inertia of the masses to be moved in opening the break er and the correspondingly longer period of time necessary to accelerate such masses.

One of the objects of the present invention, therefore, is to provide improved circuitbreaking apparatus wherein the total time elapsing from the beginning of the short-circuit until the end of the interruption is appreciably smaller as compared with such time elapsing in the interrupting or circuit-breaking action of such apparatus constructed heretofore.

Other objects and advantages will hereinafter appear.

For the purpose of illustrating the invention, several embodiments thereof are shown in the drawings, wherein Figure 1 is a diagrammatic side elevational view; and

Figs. 2 to 4 are similar views, illustrating modified arrangements.

In theembodiment of the improved apparatus shown in Fig. 1, the circuit-breaking means, designated generally by the reference numeral 10, controls the line 11 and is held in closed position by suitable spring means 12. For the purpose of effecting opening movement or circuit-breaking action of breaker 10, the same is connected through the rod 13, pivotally connected at 14, to the segment 15 loosely mounted on the shaft 16 to which is fixed the motive means 17 which may be in the form of a fly wheel rotating constantly, in the direction indicated and at substantially uniform speed, under the driving action of some suitable power means such as a motor (not shown). Disposed about the motive ele- 2eo,4os, and in Germany March 12, 1927.

ment or fly wheel 17 is the friction band 18 secured, as shown, at its ends to the armature 19 of the magnet 20 fixed to and carried by segment 15 and provided with the energizing coil or winding 21. With the parts in the position shown, with armature 19 held under the action of the tension spring 22 against the stop 23 fixed in segment 15, the friction band 18 is released from operative frictional engagement with fly wheel 17.

Upon occurrence of overload or short-circuit condition in line 11, winding 21 is excited through the transformer 24 to cause clockwise movement of armature 19 against the action of spring 22, whereupon band 18 grips fly wheel 17 to connect or couple segment 15 to the same for rotary movement therewith, the kinetic energy of the fly wheel being such as to effect substantially instantaneous opening movement of breaker 10 against the action of its holding spring 12. Suitable latching means 25 is provided to hold breaker 10 in open position, the latching means being arranged to engage the dog or detent 26 before band 18 is released by such amount as would permit the breaker to close 7 Suitable brushes 27 maintain connection between winding 21 and transformer 24 while permitting of such counter-clockwise movement of segment 15 as is necessary to effect full opening movement of breaker 10.

In the embodiment shown in Fig. 2, the arrangement is just the opposite to that in Fig. 1, in that the winding 21' is normally energized and is deenergized upon overload or short-circuit condition in line 11 to permit the tension spring 22 to impart clockwise movement to the armature 19, whereupon the friction band 18 is tightened or applied to provide an operative coupling or connection between fly wheel 17 andsegment 15', at which time the breaker 10 is opened and held in open position by the latching means 25'. Before the breaker reaches its full open position, the coupling band 18' is released by counter-clockwise movement of armature 19 to its initial position due to engagement of the lower end of the armature with a. suitable fixed stop 28 supported independently of the fly wheel and segment 15.

The coil 21 is normally excited through the transformer 24. Upon occurrence of an overload or short-circuit condition in line 11, the relay 29 operates to open the exciting circuit for coil 21, whereupon the apparatus functions as explained above. In Fig. 2 the various parts have been given primed designating characters corresponding to those designating corresponding parts in Fig. 1.

In the embodiment shown in Fig. 3, an electromagnetic clutch is used in lieu of the friction coupling band in Figs. 1 and 2. The

clutch-comprises the magnet30 disposed for radial movement between suitable guides 31 with which the segment 15 is provided, and the operating winding 32. The construction and arrangement are otherwise'as shown in Fig. 1. Upon excitation of winding 32 at overload or short-circuit condition, an electromagnetic coupling withthe fly wheel 17 is established, the latter acting as an armature. Simultaneously with this action, magnet 30 moves radially inwardly into frictional engagement with the. periphery of the fly wheel, thereby providing a better operating connection with the same. Tension springs 33 operate normally to hold magnet 30 in its outermost position out of engagement with the periphery of the fly wheel.

In the embodiment shown'in Fig. 4:, the fly wheel is provided with the conductors 34. The electromagnetic clutch comprises the magnet 30 fixed to and carried by the segment 15' and the operating winding 32. The construction and arrangement is otherwise the same as in Fig. 3. Upon occurrence of overload or short-circuit condition, the eddy currents produced by the fly wheel establish the coupling between the same and magnet 30 to cause counter clockwise movement of'segment 15" with the fly wheel and consequent opening of the-breaker. In Fig.

4: a holding coil 35, normally energized through the local circuit shown, is substituted for the spring 12 in Fig. 1. A suitable relay, 36, connected in series with the operating circuit for winding 32', operates upon occurrence of overload or short-circuit condition in the line to open the local circuit for holding coil 35 to permit of more ready open ing of the breaker by the kinetic energy.

' than has been possible in such apparatus constructed heretofore, and that the moment of .means operative upon a predetermined circuit condltion to actuate said frictional eninerita of the movable parts has been entire"- ly compensated for.

Various changes in the size, shape and arrangement of the parts may be adopted without departing from the spirit of the invention or the scope of the claims. I

The invention claimed is:

1. In electrical circuit control apparatus comprising a circuit breaker, constantly-operating motive means for actuating said circuit breaker, and means responsive to apredetermined condition of the electrical circuitand operable upon occurrence of such condition to efiect mechanical connection between said circuit breaker and said motive means.

2. In electrical circuit controlapparatus comprising a circuit breaker, constantly-operating motive means for effecting actuation of said circuit breaker, means for mechanically coupling saidmotive means with said circuit breaker, and means responsive to a predetermined circuit condition and operable upon occurrence of such circuit condition to actuatesaid coupling means to operatively connect said motive means with said circuit breaker.

3. In electrical circuit control apparatus comprising a circuit breaker, actuating means therefor, a constantly-operating motive means for actuating said actuating :means, means for frictionally engaging said actuating means with said motive means,and

gaging means to mechanically connect said motive means with said actuating means to actuate said circuit breaker. I

4. In electrical circuit control apparatus comprising a circuit breaker, actuating means therefor, a constantly-operating mo- .tive means for effecting actuation of said actuating means, electromagnetic means for coupling said actuating means to said motivecg means, and means responsive to a predeter- 1 mined circuit condition and operable upon occurrence of such condition to effect actuation of said electromagnetic means to magnetically connect said actuating means withe? said motive means to effect actuation of said 1 circuit breaker directly by said actuating means.

5. In electrical circuit control apparatus comprising a circuit breaker, constantly-op-C; 'eratmg motive means for actuating said circuit breaker, means automatically operative responsive to a predetermined circuit condition to efl'ect mechanical connectionof the said actuating means with said motive means 1 to effect actuation of said circuit breaker.

6. In electrical circuit control apparatus comprising a circuit breaker, actuating means therefor, constantly-operating motive means, means automatically operative re-v sponsive to a predetermined circuit condition to render said motive means efiective to operate said actuating means to efl'ect direct actuation of said circuit breaker by said actuating means, and means operative to main- 5 tain said circuit breaker in such actuated position.

In testimony whereof I have hereunto subscribed my name this 24th day of February LUDWIG ROEBEL. 

